Transfer device to grip a double wheel

ABSTRACT

The object of the invention is a transfer device that will grip double wheels of very different size, which is intended to move an aircraft (1) or other device equipped with double wheels on a base, which transfer device includes a fork-shaped frame and pairs of rollers (3, 4) attached to both forks (2), compression devices for them and devices to rotate the rollers, both pairs of which rollers (3, 4) being placed from the side in front and behind the wheel (6) of the device (1) to be moved. According to the invention the forks (2) are attached to the frame part (7) that connects them by means of parallelogram arms (5), which are adapted to provide the rollers (3, 4) with the lateral movement required when being placed around double wheels (6) and which transfer device includes operating devices (18) to turn the parallelogram arms.

BACKGROUND OF THE INVENTION

The invention relates generally to vehicles used to move aircraft on theground, and more particularly to moving aircraft having a double wheel.

It is desirable to provide a transfer device that grips a double, andwhich is intended to move an aircraft or other device equipped withdouble wheels on a base, and which transfer device includes afork-shaped frame and pairs of rollers located on each of the prongs ofthe fork and devices to revolve the rollers and devices to compressthem, both pairs of rollers being able to be placed from the side infront and behind the wheel of the device to be moved, and in which bymeans of rotating the rollers pressed against the wheel, the wheel ofthe device to be moved is made to revolve and the entire device to move.

Here a double wheel also means the adjacent wheels of the wheels of abogie. The transfer device is mainly intended to move passenger aircraftat an airport. Here the compression and friction rollers also mean setsof rollers formed by more than one roller close together. A track orsimilar apparatus may be used on top of the set of rollers.

The structure of a transfer device can be considerably lightened whenthe rotational force is transferred to the aircraft's own wheel from theoperating wheels or friction rollers that form part of the transferdevice. An entirely universally applicable light transfer device'sconstruction is shown in Finnish Patent Application FI 833275 (partlycorresponding to W085/01265). This requires no contact with the bogie ofthe aircraft in order to press the drive wheel against the wheel of theaircraft. The compression is achieved by means of the mutual movement ofthe pressure rollers, connected by an intermediate device, which areplaced around the wheel of the aircraft.

A transfer device, which grips a double wheel, especially the frontundercarriage bogie of an aircraft, is shown in U.S. Pat. No. 3,005,510.In it the neighbouring bogie wheels are used by means of two frictiontracks, which are wedged between consecutive bogie wheels. In the knowntransfer devices that grip double wheels the problem is that they canonly be used with some types of aircraft. The dimensions of doublewheels in different aircraft vary greatly. The smallest wheel sizes havea diameter of only 80 cm, whereas the largest diameter is a large as 2m. An even greater problem than this is the wide range of dimensionsbetween the wheels. In the smallest aircraft the distance between thetracks of the wheels is only 80 cm and in the largest 1400 cm. In thiscase a transfer device with a U-shaped frame must be made very wide andthe lateral adjustment of the rollers very long. Transfer devices with aU-frame are shown in, among others, WO publications 87/06542(PCT/FI87/53).

OBJECTS OF THE INVENTION

An object of this invention is to achieve a transfer device that rotatesdouble wheels and which can be used with double and bogie wheels ofvarying size.

SUMMARY OF THE INVENTION

The characteristics of the invention appear in the accompanying Patentclaims. The main principle of the invention is to carry out the lateralmovement of the rollers either entirely or partly by moveing the sideforks in their entirety by means of parallelogram arms. Firstly, thesekeep the forks always parallel and secondly, the torque created by thecompression is led through them to the rear frame, where the forcescancel out. In a preferred embodiment only the adjustment required bythe width of the double wheels of different aircraft is carried out bythe lateral movement of the parallelogram arms. In this case the overallwidth of the device remains small. The change in position of the frontrollers and the compression movement can be achieved in some knownmanner.

In another preferred embodiment, the forks always turn in the samerelation to the frame part. By means of a further preferred embodimentthe problem of the locking of the front support wheels can be solved.These have to turn freely during the transfer of an aircraft, but shouldbe locked when the transfer device itself is moved, when steering takesplace with the rear wheels.

The form of application shown in patent claim 6 makes possible themaximum pushing and pulling ability. The optimum locations of thecarrier wheels are at different places in pushing and pulling.

In what follows the invention is illustrated with the aid of examples byreference to the accompanying illustrations, which show various forms ofapplication of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the transfer device being driven around a double wheel,seen from in front

FIG. 2 shows the transfer device seen from the side

FIGS. 3 and 4 show the transfer device gripping a double wheel

FIG. 5 shows the use of the transfer device in connection with largedouble wheels

FIG. 6 shows one other transfer device seen from above

FIG. 7 shows the transfer device in FIG. 6 seen from the side

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

The transfer devices shown in FIGS. 1 through 7 are intended to move anaircraft 1 on an airfield. In the figures the aircraft 1 is shown byonly a part of the landing gear and the wheels 6. The transfer devicemoves to the aircraft pulled by its front support wheels 12. In additionto those its principal components are the friction rollers 3 and 4,which are supported by the front forks, their compression and rotationequipment, the power device unit, the parallelogram arms 5, the rearframe 7 and the steering device that turns the rear wheel 28. The frontforks 2 of the frame are attached to the rear frame 7 by means of theparallelogram arms 5, which can be moved by means of the operatingdevice 13. Two slides 9 are attached to each of the front forks 2, andthe rollers 3, 4 and their motors and gear-boxes are attached to them.The slides 9 are connected to one another by means of another operatingdevice 10, by means of which they and the rollers 3, 4 with them can bemoved longitudinally and the rollers can be compressed against the wheel6 of the aircraft 1.

Hydraulic cylinders are used as the operating devices 10 and 13.

In FIG. 1 the transfer device has been driven around the double wheel 6of an aircraft 1. The movement of the transfer device itself also takesplace by means of friction transmission. If there is no aircraft wheelbetween the rollers 3, 4, the auxilliary friction rollers 11 on theopposite side of the slides 9 meet the support wheels 12, which can berotated in a corresponding manner.

FIG. 2 shows the principle of the lateral movement of the forks 2. Theforks 2 include two tubes 8 and 14, along which the slides 9 move. Thesupport wheel 12 is supported by these tubes by means of the turning arm16. This arm 16 can be turned and at the same time the support wheel 12raised and lowered with the aid of a third operating device. When thesupport wheel 12 has been raised, the fork 2 descends onto the lateralauxiliary support wheel 15. After this the rollers 3 and 4 are pushed totheir extreme positions and the forks 2 are drawn inwards, in order thatthe rollers are brought into line with the track of the double wheels 6,FIG. 3. The support wheel 12 is lowered to the ground and the rollers 3and 4 are raised along with the fork 2. Finally the rollers 3 and 4 aredrawn inwards to grip the wheel 6 and its rotation begins, FIG. 4. Whenthe forks are being drawn open or closed it may happen that the secondfork 2 does not begin to move at all. In that case the rollers 3, 4 ofthe fork 2 that has begun to move are brought round the correspondingwheel 6 and pressed tight, after which the rollers of the other fork 2can also be brought into place. When moving in the opposite directionthe support wheels 12 can be separately lowered to the ground.

The transfer device in FIG. 5 is shown in connection with alarge-wheeled bogie. In the case of the wheels of a bogie two wheelsnext to each other form a double wheel, which is gripped by the transferdevice. By turning the parallelogram arms 5 quite large differences inthe sizes of double wheels can be dealt with. The movements of theparallelogram arms 5 can be synchronized by means of a transversereaction rod 17.

The entire transfer device can form an extra implement to some suitablevehicle, for example a tractor, in which case it requires no separatepower source. The vehicle is then technically regarded as being part ofthe transfer device.

In the transfer device shown in FIGS. 6 and 7 the lateral movement ofthe parallelogram arms is much less than in the devices shown in FIGS. 1through 5. This is because the front friction rollers 4 swing forwardsand the lateral movement only adapts the transfer device to differentkinds of bogies. In FIG. 6 one fork is shown in partial cross-section,so that the mechanism used to move the front friction roller 4 isvisible.

The transfer device shown in FIG. 7 is formed principally of a rearframe 7 and the forks 2, attached to it by means of the parallelogramarms 5, to which the rollers are attached. Freely turning wheels 12 arelocated at the front of the forks 2, but however these are locked inplace when the transfer device is being moved by the front frictionroller 4 (shown by broken lines), which presses on a counter member 27on the turning axle of the wheels 12. The transfer device then movespowered by the rotation device that belongs to the rear wheel 28.

The compression movement of the front friction rollers 4 takes place bymeans of swinging the parallelogram arms 22 and 23. The compression iscontrolled with the aid of a hydraulic cylinder 25. The friction roller4 is swung to the front in such a way that the triangular plate 24carried by the rear parallelogram arm 23 is swung forwards when theentire parallelogram is swung through about 85°. The swinging of thisroller as such may be effected by also using other previously knownmechanisms.

When moving an aircraft the front support wheels 12 turn freely, whichmakes it possible for the aircraft to be turned sharply. In this theforks 2 are principally constructed around the tube 37 in such a waythat suitable opening to permit the movements of the friction rollers 4are made in the tube, and the tube 37 itself forms a support frame forthe attachment of various components. Here all four friction rollers areequipped with a hydraulic motor-reduction gear unit 21.

In this the lateral movement of the fork parts 2 is carried out with theaid of a threaded rod 18, which pulls or pushes the counter members 20in the fork parts. The rotation of the screw 18 takes place by means ofa hydraulic rotation device 19, which is supported laterally from therear frame 7. Two advantages are gained here through the use of screwmembers. Firstly the movement of both forks is synchronized and secondlythe screw transmission is self-retaining.

I claim:
 1. A transfer device that grips a double wheel which isintended to move an aircraft (1) or any other double wheeled deviceequipped with a base, which transfer device consists of a fork-shapedframe and a pair of front and rear rollers (3, 4) attached to each of apair of forks (2), means for compressing and moving the forks and meansfor revolving the rollers, and in which both pairs of rollers (3, 4) canbe placed in front of and behind a wheel (6) of the double wheeleddevice (1) to be moved, and in which by rotating the rollers (3, 4)pressed against the wheels (6) of the double wheeled device to be movedthe double wheels too are made to rotate and the entire double wheeleddevice is made to move, characterized in that the forks (2) are attachedto a connecting rear frame (7) by means of parallelogram arms (5), whichare adapted to provide at least a portion of the lateral movementrequired when placing the rollers (3, 4) around the double wheels (6)and which transfer device also includes means (13, 18, 19, 20) forswinging the parallelogram arms.
 2. A transfer device in accordance withclaim 1, characterized in that both of the forks (2) include two tubeguides (8, 14) and a slide adapted to said tube guides, which areoperated by an operating device (10), to which said pair of rollers (3,4) and an operating motor is attached, such that operating device (10)moves the rollers and presses said rollers longitudinally against thewheel (6) to achieve compression.
 3. A transfer device in accordancewith claim 1, further comprising a synchronization member between theparallelogram arms (5), by means of which the arms swing by an equalamount.
 4. A transfer device in accordance with claim 1, furthercomprising a raiseable support wheel (12) and a laterally placedauxilliary support wheel (15), on which the forks (2) can be moved in alateral direction.
 5. A transfer device in accordance with claim 1,further comprising means (21, 23, 24, 25, 26) for swinging the frontfriction rollers (4) away from the track of the wheel (6) of the doublewheeled device to be moved and back in front of said wheel.
 6. Atransfer device in accordance with claim 5, which includes a rear wheelturned by steering devices and rotated by a power device, the front endsof the forks (2) further comprising support wheels (12) made to turnfreely, a turning axle of which includes a counter member (27) againstwhich the friction rollers (4) can swing and lock both support wheels(12) in a fixed direction.
 7. A transfer device in accordance with claim1, wherein said means for swinging said parallelogram arms comprises apower screw, having a threaded rod (18), counter parts (20), and arotating device, the threaded rod being locked in the centre in alateral direction, to the rear frame (7) of the transfer device.
 8. Atransfer device in accordance with claim 2, further comprising areaction rod (17) or any other synchronization member between theparallelogram arms (5), by means of which the arms turn by an equalamount.
 9. A transfer device in accordance with claim 2, characterizedin that both forks include a support wheel (12) and that the setting ofthe support height of the forks in relation to the support wheel and thefront end of each fork (2) takes place through a laterally placedauxiliary support wheel (15), on which the forks (2) can be moved in alateral direction, once the support wheel (12) has been raised.
 10. Atransfer device in accordance with claim 3, characterized in that bothforks include a support wheel (12) and that the setting of the supportheight of the forks in relation to the support wheel and the front endof each fork (2) takes place through a laterally placed auxiliarysupport wheel (15), on which the forks (2) can be moved in a lateraldirection, once the support wheel (12) has been raised.
 11. A transferdevice in accordance with claim 2, wherein the operating device of theparallelogram arms comprises a power screw, the principal components ofwhich are a threaded rod (18) counterparts (20), and a rotating device,the threaded rod being locked in the centre in a lateral direction tothe rear frame (7) of the transfer device.
 12. A transfer device inaccordance with claim 5, wherein the operating device of theparallelogram arms comprises a power screw, the principal components ofwhich are a threaded rod (18) counterparts (20), and a rotating device,the threaded rod being locked in the centre in a lateral direction tothe rear frame (7) of the transfer device.
 13. A transfer device inaccordance with claim 6, wherein the operating device of theparallelogram arms comprises a power screw, the principal components ofwhich are a threaded rod (18) counterparts (20), and a rotating device,the threaded rod being locked in the centre in a lateral direction tothe rear frame (7) of the transfer device.
 14. A transfer device thatgrips a double wheel, which is intended to move an aircraft (1) or anyother double wheeled device equipped with double wheels on a base, whichtransfer device consists of a rear frame (7), a pair of forks (2), and apair of rollers (3, 4) attached to both of said forks (2), means forcompressing and moving the forks and means for revolving the rollers,and in which both pairs of rollers (3, 4) can be placed in front of andbehind a wheel (6) of the double wheeled device (1) to be moved, and inwhich by rotating the rollers (3, 4) pressed against the wheels (6) ofthe double wheeled device to be moved, the wheels (6) are made to rotateand the entire doubled wheeled device is made to move, said transferdevice comprising:a. parallelogram arms (5) connecting said forks (2) tosaid rear frame (7) so as to effect lateral movement of said forks (2)when placing the rollers (3, 4) around the double wheels; and b. meansfor turning the parallelogram arms.